@@ -19,13 +19,15 @@ Measures measuring the same propriety are grouped together in tables and graphs,
***etf_offset**: When a packet\s txtime is scheduled, the txtime set is the current time offset by etf_offset
***route**: How the boards are connected. switch means they are connected by a switch (cheap, unmanaged), E2E
***qdisc**: qdisc used to send packets
***client**: Device which sent the packets
***XDP**: Were XDP sockets used
### cyclictest_wake-up_latency results
Uses cyclictest from the rt-tests test suite to measure wake-up latency. A real-time thread is run on CPU1, and wakes up at a regular interval (specified by the interval parameter) using clock_nanosleep. It then uses clock_gettime and computes the difference between the scheduled wake-up time and the effective wake-up time measured by clock_gettime.
The command used is: cyclictest -p `prio` -a1 -t1 -n -h 200 -q -i `interval`
Two shuttles connected end to end with an ethernet cable and synchronized with PTP emit signals, and a logic analyzer measures variation in those signals, similar to "Shuttle controlled A20 signal output jitter" measures
**Common test metadata:** Device: Shuttle, Linux kernel version: 4.19, Task priority: 98, Interval: 10000us, Boot Parameters: isolcpus,rcu_nocbs,irqaffinity, ETF qdisc delta: None, Device and processor load: None, Test duration: 0h10, Speed (Mb/s): 1000, ETF offset: 500us, Packet route: E2E, qdisc: pfifo_fast
**Common test metadata:** Device: Shuttle, Linux kernel version: 4.19, Task priority: 98, Interval: 10000us, Boot Parameters: isolcpus,rcu_nocbs,irqaffinity, ETF qdisc delta: None, Device and processor load: None, Test duration: 0h10, Speed (Mb/s): 1000, ETF offset: 500us, Packet route: E2E, qdisc: pfifo_fast, Client device: A20, XDP: no
Minimum | Maximum | Average | Standard deviation | Lost packets
![alt text](measures/graphs/shuttle_signal_jitterShuttle signal output jitter.png "shuttle_signal_jitter Graph")
### packet_jitter results
An UDP packet is periodically sent from one board to another using a real time thread. The receiving board calculates the intervals between the packets it receives, and sees how much it differs from the scheduled interval.